How to convince a science denier to reconsider their beliefs

It's possible to change the mind of someone who holds views that aren't backed up by scientific evidence, according to science philosopher Lee McIntyre.

Science denialism comes in many forms: climate change deniers, people who are anti-vaxxers, who believe COVID is a hoax, that evolution isn't real, and who think the Earth is flat. 

With the COVID-19 pandemic and climate change creating huge challenges for humanity, denying science has never been so dangerous. 

So, what can you do if that science denier is someone you care about — or maybe even someone in your family? 

McIntyre, a research fellow at the Center for Philosophy and History of Science at Boston University, decided to explore this topic in a new book titled, How to Talk to a Science Denier: Conversations with Flat Earthers, Climate Deniers, and Others Who Defy Reason. 

McIntyre spoke to Quirks & Quarks host Bob McDonald about how science deniers construct and defend their beliefs with evidence-based insights into how to change their minds. 

Here is part of their conversation.

You write in your book that there's a common script behind all science denial reasoning, and that if we know the script, we can change it. So, what is the script? 

This script was discovered by Mark and Chris Hoofnagle, and it was developed further by John Cook and Stephen Lewandowsky, who are cognitive scientists and it goes like this: there are five tropes of science denial reasoning.

Every science denier cherry picks data, believes in conspiracy theories, engages in illogical reasoning, relies on fake experts and denigrates real experts, and here's my favourite: that science has to be perfect in order to be credible. 

Now, if you understand that script, you're way ahead of the game. 

There was a study in Nature Human Behavior in June of 2019 which vindicated that model. It's called technique rebuttal and I was very gratified to see that that was really the first empirical evidence to show that it could be effective in convincing science deniers to give up their beliefs. 

When you say technique rebuttal, what do you mean by that? 

Technique rebuttal is simply to understand those five tropes and to learn how to use that to push back. So, for instance, somebody who claims that science has to be perfect to be credible.

Often, I would say to the flat Earthers something like, "OK, so you claim that you're being more scientific than the scientist?"

"Yes." 

"And your beliefs are based on evidence?" 

"Yes."

"So what evidence would it take to convince you that you were wrong?"

They weren't prepared to talk about that. And my experience is that if you listen to somebody and you make it clear that you're respecting them as a person — even if you're not respecting their belief, but you asked them why they believe it — they'll eventually say something that you can use.

They'll say something illogical. They'll say something that relies on a fake expert. And that can give you an opening to at least plant that seed of doubt to say, "Well, wait a minute. Are all the pictures from NASA faked?"

There's sort of a general theme in the book that science deniers have a fundamental misunderstanding of how science works, that the deniers may already have their conclusion before they begin and look for evidence to fit that, which is backwards to the way science works. 

The thing I respect the most about scientists is that they test their biases against the evidence. And, by the way, they can answer that question that I posed to the flat Earthers. If you ask a scientist what evidence could change your mind about hypothesis X, they can tell you. 

What makes a denier is not somebody who rejects the scientific consensus. It's somebody who rejects the scientific consensus and doesn't have good evidence for their beliefs and won't say what evidence would convince them to give up their beliefs.

That's when they're in this kind of hermetically-sealed box where the evidence can't get to them. And that's just the exact opposite of what I call the scientific attitude. 

You also mentioned in the book a technique called content rebuttal. How does that work? 

Well, content rebuttal is another method that Betsch and Schmid talked about in their article. That's a little tougher to do because you have to actually be an expert.

If you're a climatologist and you're having a discussion with a climate denier and they're bringing up the false claim that the global temperature hasn't gone up in the last 17 years — or whatever it is they're claiming right now — you know the studies and you know the data and you can push back with content. 

Now, in that study, they looked at both content rebuttal and technique rebuttal side by side and found that they were both equally effective and that there was no additive effect, which is spectacular news for the allies of science because it means that even though I'm not a scientist, I can go out there and be just as effective as a scientist is using content rebuttal, by me using technique rebuttal. 

Produced and written by Sonya Buyting. This Q&A has been edited and condensed.